Canon baterries

ok ive got 2 more batteries from a broken canon G3 that i plan to use on the 40D but have a bit of concerns, i got a original canon bp-511 7.4v 1100 mah li-ion and a aftermarket one that worked fine on the G3 BP511 7.2v 1350mah li-ion. these being same almost volt but mah a bit lower going to hurt the camera, think its not going to last as long but im not to concerned cause it will just be backups ussage if first original canon one does not last.

The 40D takes all the following batteries as stated in the manual:
BP-511A, BP-511, BP-514, BP-512.

So yes, it will be fine with the BP-511.

thank u batteries are cheap camera aint. thanx

mAh is how long it'll run, essentially. They'll work fine, just not for as long as something with more mAh.

i have got batteries on ebay no problem - 2 for $12.00